<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<script>
    var admin = prompt('请输入用户名：');
    var pwd = prompt('请输入用户密码:');
    while (admin !== 'admin' && pwd !== '123456'){
        admin = prompt('请输入用户名：');
        pwd = prompt('请输入用户密码：');
    }
    alert('登录成功！');
</script>
<body>

</body>
</html>